This is a long-term, continuing program encompassing a number of basic problems related to transport mechanisms of gametes in the female reproductive tract. The areas of emphasis are: 1. The role of smooth muscle in gamete transport within the oviducts. 2. The role of cilia in gamete transport within the female reproductive tract but especially within the oviducts as well as a study of ciliary physiology, pharmacology and endocrinology. 3. The controlling mechanism involved in sperm transport through the uterotubal junction. 4. Changes in the fine structural characteristics of the oviductal mucosa during the reproductive cycle as studies with the scanning and transmission electron microscopes. 5. Chracterization of sperm membrane changes during their transport through the female reproductive tract. Bibliographic references: Blandau, R.J., J.L. Boling, S.A. Halbert and P. Verdugo 1975 Methods for studying oviductal physiology. Gynec. Investig., 6: 123-145; Rumery, R.E. and R.J. Blandau 1975. The response of transplants of cultured fetal mouse ovaries in kidneys of ovariectomized adult mice. Submitted to J. Morph. for publication.